#include <bits/stdc++.h> using namespace std; int a[200][200], n, m; int main(){ cin >> n >> m; for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) cin >> a[i][j]; int sum = 0; for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) if (i == 1 || i == n || j == 1 || j == m) sum += a[i][j]; cout << sum << endl; return 0; }